The invention is directed to patient supporting tables having a support plate with a seating surface for a patient and a cut-out through which the body surface of a patient lying on the seating surface is accessible for medical purposes. The invention is also directed to patient supporting tables comprising a base member that carries the support plate such that the support plate is adjustable relative to the base member.
Patient supporting tables of the type described above are required for a great variety of applications wherein it is necessary that the body surface of a patient be accessible through the cut-out, whether to permit an operative procedure to be performed or to permit application of a medical device, for example, a lithotriptor, to the body surface of the patient. The support plate is adjustable relative to the base member in order to be able to position the patient as desired.
Such a patient supporting table is disclosed and described in a brochure published by Siemens AG, and entitled: "LITHOSTAR Universeller urologischer Arbeitsplatz fuer Therapie und Diagnostik". The printing reference number is A91001-M1027-G490-01 PA 4864.
In the disclosed patient supporting table, a shockwave source is arranged under the support plate and the table is provided with a rectangular cut-out. The shockwave source is provided for outputting focused shockwaves for disintegrating calculi, for example kidney stones, situated in the body of the patient.
For such a treatment, a shockwave tube is brought into engagement with the body surface of a patient lying on the support plate through the cut-out of the support plate. The tube then is acoustically coupled to the body surface of the patient so that the calculus to be disintegrated is situated in the focus of the shockwaves. Under the influence of a series of focused shockwaves generated by the shockwave tube, the calculus disintegrates into fragments that can be eliminated in a natural way.
In order to be able to bring the calculus to be disintegrated into the focus of the shockwaves, an exact positioning of the patient relative to the shockwave tube is required. Thus, the disclosed patient supporting table provides means including a drive motor for displacing the support plate together with the patient lying thereon relative to the base member and the shockwave tube along the longitudinal direction of the table and/or transversely relative thereto.
In order to prevent the patient (who may be sedated or even anesthetized under certain circumstances) from falling through the cut-out, the cut-out has only relatively small dimensions in the longitudinal direction of the table. Moreover, since the shockwave tube is arranged in the cut-out of the support plate during the displacement of the support plate, the support plate can be displaced only by a slight dimension in the longitudinal direction of the table relative to the shockwave tube. Otherwise, edges of the cut-out would strike against the shockwave tube and displace it out of its predetermined position, or worse, damage it.
Therefore, attending physicians and attending personnel must first manually align the patient at least in the longitudinal direction of the table with sufficient precision on the support plate so that the range of adjustment of the support plate limited by the dimensions of the shockwave tube and of the cut-out is adequate for an exact positioning of the patent. In view of the fact that the patient can be sedated or anesthetized, this involves considerable physical exertion on the member of the attending physicians and the attending personnel. Moreover, there is also the risk that a patient who, for example, is already is exactly positioned in the transverse direction of the patient supporting table will be in turn dislocated out of that position. Further, the described procedure is not particularly gentle on the patient since considerable forces can be exerted on the patient.